Increased performance, both with regard to more complex functionality and higher speeds, is a continuing goal of efforts in advancing the semiconductor arts. One method that has been used for achieving this goal is scaling downward the size of individual devices used in forming advanced semiconductor integrated circuits. However, it is found that at times, changes in the components used in fabricating such down-sized devices are advantageous. For example, where capacitors, such as those used in memory integrated circuits, are scaled downward in size, dielectric materials such as silicon oxide and silicon nitride are often replaced with alternate materials having a higher dielectric constant to achieve desired capacitance. Where such replacements of dielectric materials are made, it can be advantageous to form capacitor electrodes comprising one or more of platinum, tantalum, ruthenium, iridium, and titanium. Such electrodes can comprise, for example, alloys of various metals and/or nitrides of various metals, including, for example, titanium nitride. The capacitors comprising metallic electrodes are well known in the art, and are frequently described as metal-insulator-metal capacitor constructions.
One method for patterning various dielectric and conductive materials is chemical mechanical polishing (CMP). A material (such as platinum), can be blanket formed within an opening and over surfaces proximate the opening. The material can be removed from over the surfaces by a CMP method. The material within the opening, elevationally below that upper surface, will not be removed. The material within the opening can ultimately form a capacitor electrode structure. A problem with the CMP method can be scratching or smearing of the material, which can prevent the proper forming of the ultimately desired capacitor structure. For instance, if the material is platinum or an alloy of platinum, scratching or smearing of the platinum can occur in a CMP process. It can be difficult, and for all practical purposes impossible, to remove smeared platinum from within a container.
It would be desirable, to develop a CMP method where the removal of portions of various materials (such as platinum or barrier materials) can be effected without scratching or smearing across surfaces of the materials. It would also be desirable if such a CMP method was cost-effective and could be performed using essentially standard CMP processing tools.